The science of chiropractic involves the selective adjustment of any abnormal articulations of the human body, especially those of the spinal column, for the purpose of assuring full and free range of motion, and freeing impinged nerves that may cause pain or deranged function. Careful, skilled manipulation of the spine, therefore, is central to effective chiropractic treatment.
Moreover, to maintain the condition of the spine and the tone of the contiguous soft tissue structures, it is often advantageous to manipulate the spine to achieve better alignment of its component parts. Typically this manipulation is done manually by a therapist with the patient lying on his or her abdomen or back. For example, with a patient lying on his abdomen, the therapist may attempt to realign a vertebra by imparting a manual force to it while holding the adjacent vertebra stable. This technique, while frequently effective, is highly dependent on the therapist's physical strength and skill in performing the manipulation, and is limited by physical constraints including the size and health of the patient and the inherent fact that the spine is in a static condition (i.e., is oriented in a generally fixed, unmoving position as the patient lies on the treatment table).
It is also advantageous to treat injuries to and conditions of the spine by having the patient perform various exercises in an active/passive regime designed to achieve better alignment of the spine and tone of adjacent soft tissue structures, i.e., nerves, muscles, ligaments, tendons and blood and lymphatic circulation. Again, however, such excercise is limited by the patient's physical strength and coordination, and other factors that may inhibit the proper excercise needed, both in terms of degree and direction of movement and duration of the excercise.